People with HIV/AIDS May Be More Prone to Sudden Cardiac Death

In a comprehensive, retrospective 10-year UCSF study, researchers found patients with HIV/AIDS suffered sudden cardiac death at a rate four times higher than the general population.

"As part of my ongoing research in 2010, we were looking at every instance of sudden death in San Francisco," said first author Dr. Zian H. Tseng, an electrophysiologist and an associate professor of medicine in the UCSF Division of Cardiology. "I noticed that many of these cases involved individuals with HIV infection, who were dying suddenly. I wondered if there was some sort of connection there."

He posed this question to Dr. Priscilla Hsue, a UCSF associate professor of medicine and the director of the HIV Cardiology Clinic at San Francisco General Hospital and Trauma Center (SFGH), who is one of a few cardiologists in the country who specializes in HIV. To her knowledge, no one had ever explored the link between HIV and sudden death, and that is when they began collaborating on this research.

In a paper scheduled to be published May 15 in the Journal of the American College of Cardiology, Tseng, Hsue and other researchers conducted a retrospective study of 2,860 HIV patients from April 2000 to August 2009 at SFGH's Ward 86, the first HIV/AIDS-specialized clinic, to comprehensively characterize all deaths. They studied medical records, death certificates, paramedic reports, and interviews with family members, doctors and other clinicians.

Sudden Cardiac Death and HIV/AIDS

During that period, 8 percent died during an average of 3.7 years of follow up. Cardiac-related deaths accounted for 15 percent of overall mortality. Of that group, 86 percent died of sudden cardiac death.

"To put that in context, we're able to compare the rate of sudden death in this population with the overall San Francisco population," Tseng said. "So adjusted for age, race, demographics and other variables, the rate of sudden death in the HIV population is more than four times higher than the general population."

"The fact that the vast majority of cardiac deaths were sudden is surprising and implies that we as clinicians need to be aware of this potential health issue among patients with HIV," Hsue added."Our findings also highlight many things that we still don't know about HIV and sudden death. Did these individuals die of unrecognized coronary artery disease? What can we be doing as clinicians to identify patients at risk and to intervene beforehand?"

Categorizing Sudden Cardiac Death

By 2003, sudden cardiac death made up the largest number of non-AIDS deaths among HIV-positive patients in San Francisco. These deaths were largely among individuals with evidence of well-controlled HIV disease.

Researchers used well-published criteria for retrospectively identifying death as either HIV-related or sudden death-related. If there was any doubt, they classified sudden death as an HIV death.

"In other words, for someone with a CD4 (T-cell) count less than 50 who died suddenly, we classified that as an HIV death, rather than a sudden death because of the profound immunodeficiency," Tseng said.

More than 17,000 people with AIDS in the United Stated died in 2009, and more than 619,000 people have died since the epidemic began. Still, the number of people living with HIV continues to rise. More than 1.2 million people in the United States are HIV-positive, according to the U.S. Centers for Disease Control and Prevention.

"Now that HIV-infected individuals are living longer with the benefit of antiretroviral therapy, non-AIDS conditions are becoming increasingly important and at the top of this list is cardiovascular disease," Hsue said.

Researchers believe HIV changes the electrophysiology of the heart in a way so pronounced that it causes conduction abnormalities. And many HIV medications can throw off the heart's electrical cycle, which increases the risk of sudden death. These and other variables could be contributing factors.

"Acknowledging the limitations of a retrospective analysis, what's interesting about this study is that it opens up many related questions we can ask in future studies, such as which high-risk patients might benefit from defibrillator implantation?" Tseng said.

Tseng is in the middle of a prospective citywide study on sudden cardiac death, including studying HIV patients and monitoring their progress.

Tseng is the first author of the paper; Hsue is the senior author; co-authors include Dr. Eric Secemsky of the UCSF Department of Medicine; Dr. David Dowdy of the Johns Hopkins Bloomberg School of Public Health's Department of Epidemiology; Eric Vittinghoff of the UCSF Department of Epidemiology and Biostatistics; Dr. Brian Moyers of the UCSF Division of Cardiology; Dr. Joseph Wong of the UCSF Department of Medicine and San Francisco VA Medical Center; and Dr. Diane Havlir of the San Francisco General Hospital HIV/AIDS Division.

This study was supported by funds from the U.S. National Institutes of Health (NIH). Tseng has received minor honorarium from Biotronik. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

About UCSF Medical Center
UCSF Medical Center consistently ranks as one of the top 10 hospitals in the United States. Recognized for innovative treatments, advanced technology, collaboration among health care professionals and scientists, and a highly compassionate patient care team, UCSF Medical Center serves as the academic medical center of the University of California, San Francisco. The medical center's nationally preeminent programs include children's health, the brain and nervous system, organ transplantation, women's health and cancer. It operates as a self-supporting enterprise within UCSF and generates its own revenues to cover the operating costs of providing patient care.